Electron discharge device



,1934. v. L. RONCI ET AL ELECTRON DISCHARGE DEVICE 17, 1951 2Sheets-Sheeti- Filed Dec.

By JRLA/CO a N O L V S R m N W m EQEEMM A TTORNEV 1386- 18, 1934- v. L.RONCI ET AL ELECTRON DISCHARGE DEVICE 2 Sheets-Sheet 2 Filed Dec. 17,1931 1 L.RONC/ INVENTORS JPLA mo A TTORNEK Patented Dec. 18, 1934ELECTRON DISCHARGE DEVICE I Victor L. Ronci and Joseph P. Laico,Brooklyn, N. Y., assignors to Bell Telephone Laboratories,-Incorporated, New.York,' N. Y., a. corporation" of New York ApplicationDecember '17, 1931, Serial No. 581,548 12- Claims. (01. 25o 27.5

This invention relates to electron discharge devices and moreparticularly to such devices of high power capacity.

An object of this invention is to preventexcessive changes in the spacerelation of the'electrodes of an electron discharge device during theevacuation treatment and during the operating life of the device.Another'object of this invention is to facilitate the accurate alignmentof the several elec'-' trodes in an electron discharge device.

A further object of this invention is to expedite the assembly andmanufacture of electron discharge devices.

In one embodiment, an electron discharge device constructed inaccordance with this invention, comprises'a double-ended enclosingvessel in which an anode assembly is supported from one end of theenclosing vessel and a unitary cathode and control electrode or gridassembly is supported from the other end of the vessel. The cathode andcontrol electrode or grid assembly comprises a pair of rigid frameswhich ex-.

tend parallel to each other within the anode. An insulating block iscarried by the frames and supports a plurality of resilient hookmembers. A filamentary cathode is suspended between the hook members andconductors extending from the stem. A pair of uprights are yieldinglysupported between corresponding-arms of the frame members and carry ahelical wire control electrode or grid which encircles the cathode andsubstantially conforms .in contour to the shape of the anode. Inaccordance with one feature of this "invention, the grid uprights aresupported from the frame by flexible arms which allow. both lateral andlongitudinal expansion of thecontrol electrode or grid with temperaturevariations during the out-gassing treatment of the electrodes and duringthe operation of the device and there by maintain the grid in properspace relation with respect to the cathode and anode. I v

The grid-cathode structure forms a compact, rigid unitary assembly whichhas a relatively large degree of freedom of movementwithin the anode andmay also vibrate as a whole on the. supports. This substantiallycushions the assem bly against shocks 'to which thedevice may besubjected during transportation or mounting and thereby prevents damageof the electrodes The structure is suificiently rigid, however, tomainta'n the proper space relation of the cathode and grid within theanode during the operation of the device. ,3 p i The various features ofthe invention will be understood more clearly from the followingdetailed description with reference to the accompanying drawings inwhich: y,

I Fig. 1 is a perspective view of an electron di sor grid showing chargedevice constructed in accordance with this invention with a portion ofthe enclosing vessel and the "anode broken awayto show the electrodeassembly more clearly;

Fig. 2 is a perspective view of the cathode-grid assembly employed inthe device shown in Fig. 1;

Fig- 3, is an enlarged detail view in perspective illustrating themounting of the cathode supporting insulatorfrom the grid frames,aportion of the insulator and one of the frames being broken away toshow the construction more clearly; 1 4 I Fig. 4 is an end View of thecontrol electrode the configuration ofthis electrode; I

Fig- 5 is an enlarged detail view incross-section along line 5-5 of Fig.2;

Fig. 6 is an enlarged detail View in perspective ofa, flexibleiarmfor'supporting one of the grid uprightsfromthe grid frames;

Fig. '7 is an enlarged detailside view illustrating thecon nection'ofone of the'fiexible arms to the grid upright and the grid frames;

? Fig. 8 is a perspective View of theanode assembly in the device shownin Fig. 1; and I Fig. 9 shows the form of the cathode and itsassociation with the leading-in conductors.

Referring now to Fig. 1 of the drawings, an electron discharge device,in one embodiment of this invention, comprises a double-ended enclosingvessello having reentrant stems 11 and 12 at oppositeendsthereof. The.stems 11 and 12 terminate in ,isubstantially rectangular presses, 13 andlrespectively, which are disposed at substantially right angles to eachother. An anode assembly, shown more clearly'in Fight-is supportedfromthe stem 12, and aunitary cathode and. control electrode or gridassembly, shown more clearly in Fig, 2 .-is supported from the stem 11.5 v

The cathode and control electrode or grid assembly-comprises a pluralityof spaced split metallic bandsor collars each having similar opposedarcuate portions 15 and 16 and integral flanges 1'7 andf18 at the endsthereof which are clamped on the stem 11 by bolts 19 and nuts 20. Aplurality of inverted L'-shaped rigid wires 21- are afixed to thearcuate portions 15 and 16 of the split bands or collars and carry tworigid U-shaped wire frames 22 which extend parallel to'each other and tothe longitudinal axis of the enclosing vessel 10. A pair of metallicstrips 23 are secured in any suitable manner for example by-welding,between contiguous arms of the frames 22 at the end ofthe framesadjacent the rigid wires 21 and each strip has secured thereto a,flexible or resilient U-shaped metallic finger or strip 24, as shownclearly in Fig. 7. A pair of flexible or resilient metallic T-shapedfingers 25 are secured in any suitable manner,

during the operation of the device. 'The flexible fingers maintain thecontrol electrode or grid 2'7 in its proper form and position andprevent the setting up of deleterious stresses in the lateral wires ofthe grid.

In the fabrication of the control electrode or grid it sometimes occursthat the lateral grid wires are slightly bent inwardly, and as a result,when the lateral wires become heated during the operation of thedevice'there is danger of their expanding inwardly and contacting with acooperating electrode, such as a filamentary cathode, within the grid.To avoid this difficulty the convolutions of the grid 27 may be formed,as shown in Fig. 4, with substantially parallel intermediate portionsand tapering or substantially V-shaped end portions. When the grid ofthis form becomes heated, the intermediate portions necessarily moveoutwardly, because of the expansion ofthe end portions so that even ifthe portions are accidentally bowed inwardly during the process ofassembly, sufficient clearance will be maintained to prevent contact ofthe grid wires and an electrode within the grid.

In the assembly of the grid structure, the frames 22 are preferablywelded to the wires 21 before the wires are attached to the bands orcollars 15 and 16. This enables the rotation of the wires 21 about thelongitudinal axes of the arms thereof parallel to the frames to 'alimited extent due to the depth of the weld between the frame 22 andwire 21. After this weld is made the wires 21 are Welded to the collars15 and 16 and no abnormal stresses are introduced into the wires 21 orframes 22.

The cathode is suspended from the grid structure by means of a support30 which is clamped between the grid frames 22 as clearly'shown in Fig.3. This support comprises a block of insulating material, such asflavite, provided with end grooves 31 onthe longitudinal surface inwhich the short portions of the frames 22are seated. The block 30isformed with a plurality of bores 32 and circular recesses 33, andcarries a plurality of helical springs which are seated in the recesses33. These springs support metallic hook members 35 the shanks of whichpass through the bores 32 and the hooks engage the apices of afilamentary cathode to. be described in detail hereinafter. The block 30is further formed at its ends with slots 36 in which theends of the gridsupports 26 are disposed out of contact with the block, and is providedwith longitudinal cut-out portions or recesses 37 intermediate the endgrooves 31 which form an open space on each side of the block betweenthe ends of the grid frames 22 and the block. Since the grid frames 22are in engagement with the block 30 only in the grooves 31 a resistancepath of maximum length through the block 30 is provided between theframes 22 and the hook members 35 so that very high insulation'isobtained between the grid 27 and the cathode.

The cathode, as shown more clearly in Fig. 9 consists of a plurality ofv shaped sections 38,

39 and 40, preferably of thoriated tungsten wire,

%2embedded in the press 13.

heating to high temperatures.

which are disposed uniformly within the grid 27 and are suspendedbetween the hook members 35. and a pair. of U-shaped members 41supported adjacent the stem 11 by short rigid wires The rigid wires 42are electrically connected by leading-in wires 45 tocertain of theterminal pins 43 carried by an insulating based; which is attached toone end of the enclosing vessel 10. As is evident from Fig. 9, in whichthe arrows indicate the direction of current flow, the sections 33, 39and of the cathode are electrically connected in parallel so that arelatively low voltage source may be utilized for supplying the heatingcurrent to the cathode. It is also possible. to ob tain with thisarrangement a low potential drop through the sections of the cathode anda uniform electron emission throughout the length of the cathode.

' The control electrode or grid 27 is electrically connected to one ofthe terminal pins 43 by a leading-in conductor 46 which is sealed in thewall of the stem 11 and is connected to one of the grid frame supportingwires 21 by a metallic band 47.

The grid frames 22 are vibratile about the point of attachment to thebent wires 21, so that the grid and cathode assembly is capable ofmovement substantially as a whole. This protects the assembly againstshocks to which the device may be subjected during shipment or mountingand thereby protects the cathode and grid against damage. The structureis sufficiently rigid, however, to maintain the grid-cathode assembly inproper space relation within the anode during the operation of thedevice. 7

An anode assembly, shown clearly in Fig. 8, comprises a flattenedcylindrical anode as uniformly disposed about the grid 2'7 andsubstantially conforming to the contour thereof. The anode consists oftwo similar opposed U-shaped portions having large surface integralflanges 49 which are joined by integral bent tabs 50, the ends of theflange of one section being 'crimped about the edge of the correspondingflange of the other section as shown at 51. The U-shaped portions of theanode are provided with parallel corrugations or embossments 52, toprevent excessive distortion of the anode by The anode is supported fromthe stem 12 by a pairof split metallic bands or collars 53 and 54 whichare clamped about the stem 12 by bolts 55 and nuts 56 passing throughflanges 57 and 58 integral with the bands or collars. A pair of rigidhairpin-shaped metallic frames 59 and 60 extend from the collars 53 and54 parallel to the longitudinal axis ofthe enclosing vessel, and eachsupports a rigid wire frame or hanger 61 and 62 respectively. The framesor hangers 61 and 62 pass through apertures in the end of the flanges 19remote from the stem 12 and are bent as at 63 to prevent movement of theflange along the end of the frames. A pair of rigid bent wires 64 and 65extend from the press 14 and carry hook members 6 6 and 67 respectivelywhich pass through apertures in the end of the flanges 49 of the anode,nearest the stem 12 and are secured as by welding to the frame members59 and 60 respectively. This construction, which is described in greaterdetail and claimed in a copending application of V. L. Ronci and J. E,Clark, Serial No. 530,198, filed April 15, 1931, accurately positionsthe anode is, allows longitudinal"movem"ent of the anode, and insuresuniform expansion and. contraction thereof during the operation of thedevice. The anode 48 is electrically connected to an external terminal68 carried by a flanged insulator 69 secured to the enclosing vessel 10,through leading-in conductors 70 sealed in the stem 12 and attached tothe bent wires 64 and 65.

A grooved getter ring support 71 carrying a quantity of vaporizablematerial, such as magnesium, for fixing residual gases within the ves-Sol 10, is supported from the band or collar 54 by a metallic strip 72.I

Although a specific embodiment of this invention has been disclosed anddescribed, it is, of course, to be understood that various modificationsmay be made in the assembly, without departing from the scope and spiritof the invention'as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising an enclosing vessel having astem, a plurality of rigidly interconnected metallic frame membersextending from said stem, and a plurality of electrodes resilientlysupported by said frame members, one of said electrodes beingelectrically connected to said frame members and another of saidelectrodes being insulated from said frame members.

2. An electron discharge device comprising an enclosing vessel having astem, a plurality of rigid frame members supported from said stem, acathode insulatingly suspended from said frame members, a helicalelectrode encircling said cathode, and means connected to said framemembers at spaced points intermediate the ends thereof and flexiblysupporting said helical elec trode from said frame members.

3. An electron discharge device comprising an enclosing vessel having areentrant stem, a collar clamped about said stem, a pair of parallelU-shaped metallic frame members carried by said collar, an insulatormounted on said frame members at the end thereof remote from said stem,a rigid conductor embedded in said stern, a filamentary cathoderesiliently suspended from said insulator and connected to saidconductor, a helical grid electrode encircling said cathode,electrically conductive means connected to said grid electrode and tosaid frame members and resiliently supporting said grid electrode. fromsaid frame members, and an anode surrounding said cathode and gridelectrode.

4. In an electron discharge device, an electrode assembly comprising aplurality of metallic frame members, parallel metallic supportingmembers disposed between said frame members, flexible electricallyconductive means connecting said sup V porting members to said framemembers, and a helical wire electrode mounted on said supportingmembers.

5. An electron discharge device comprising an enclosing vessel having astem, a pair of frames having parallel arms supported from said stem, arectilinear rod disposed between adjacent arms of said frames, resilientmeans supporting said rod from said frames allowing both lateral andlongitudinal movement of said rod, a helical grid electrode carried bysaid rod, a cathode Within said grid electrode, and an anode adjacentsaid grid electrode.

6. An electron discharge devicecomprising an enclosing vessel having astem, a unitary assembly mounted on said stem including a plurality ofparallel frames, a plurality of rigid parallel supporting members,resilient means connecting opv posite ends of said supporting members tosaid frames, a helical Wire electrode mounted on said supportingmembers, an insulating member carried by said frames, and a cathodesuspended from said insulating member and disposed within said helicalelectrode.

7. In an electron discharge device, an electrode assembly comprising aplurality of juxtaposed frames, a plurality of laterally andlongitudinally flexible members-connecting said frames, a plurality ofparallel rigid rods supported by said flexible members, and a helicalwire electrode mounted on said rods.

8, An electron discharge device comprising an enclosing vessel having areentrant stem, a plurality of collars clamped about said stem, a pairof parallel U-shaped frames extending from said collars, a plurality ofpairs of spaced flexible members supported between. juxtaposed arms ofsaid frames, a rigid rod carried by each pair of said flexible members,a helical wire electrode carried by said rods, an insulating supportclamped between said frame members, a filamentary cathode disposedwithin said electrode and suspended from said insulating member, and ananode encircling said cathode and said electrode.

9. An electron discharge device comprising an enclosing vessel having astem, a plurality of collars clamped about said stem, a plurality of L-shaped supports each having one arm parallel to the longitudinal axis ofsaid stem secured to said collars and an outwardly extending arm atsubstantially right angles to said axis, a plurality of U-shapcd framemembers having their ends attached to said outwardly extending arms, acathode and a grid electrode supportedfrom said frame members, and ananode adjacent said cathode and grid electrode.

10. An electron discharge device comprising an enclosing vessel having areentrant stem at each end,a frame supported from one of said stems, a

cathode suspended between the top of said frame and said stem supportingsaid frame, a helical grid electrode encircling said. cathode, resilientmeans mounting said grid electrode from said frame for both lateral "andlongitudinal movement, a plurality of frame members extending from theother of said stems, an anode disposed about said cathode and said gridelectrode, and means mounting said anode from said frame members ing theends of said rods to the adjacentarms of said frame, said members beingflexible to allow lateral and longitudinal movement of said rods.

12. An electrode assembly for an electron discharge device, comprising aframe having a plurality of parallel arms, a plurality of rigid rods,one adjacent each of said arms, a helical Wire electrode carried by saidrods, a plurality of flexible U-shaped members connecting one end ofeach of said rods to the adjacent arm of said frame, and a plurality offlexible members connecting the other end of each of said rods to thecorresponding arm of said frame.

. VICTOR L. RONCI.

JOSEPH P. LAICO.

